The Motherlode Quest
To start the Fallout 76 The Motherlode quest, you’ll need to seek out Hornwright Industrial Headquarters. Located in the Forest, this tall building has cyan blue panelling and is clearly visible from quite a distance. Like many locations in the game, you’ll receive a miscellaneous quest as you approach for the first time. Simply follow where that quest directs you; to the foyer terminal. Read the archived messages on that terminal in order to start The Motherlode quest proper.
Once the quest has begun, make your way up through the tower. Expect the building to be inhabited by ghouls and scorched. However, given that you’re in the Forest, these enemies are unlikely to be much of a threat to even mid-level players. Once you reach the second floor from the top, look for the terminal belonging to Penelope Hornwright. On this machine, read the message; “Archived Message – 9.30.77,” and this will give you the Hornwright HR Password.
From there, head back down to the third floor to find the Human Resources department. As soon as you enter the department, turn right and look for filing cabinets. You should find an ID Card Printer on top of them, below a clock. You can use this to print an executive key card. However, the printer won’t allow you to print anything just yet.
Call Up The Motherlode
With the ID in hand, return to the bottom floor and find an elevator, which is in the northeastern part of the room. Your ID can be used to access this elevator and ascend to the exclusive executive floor. Here, head for the room on your left to find the External Connection Systems. At this stage, you should receive an objective to search for a repair beacon. Go up the nearby steps and look around for a red terminal. On this machine, select the “Power Struggles,” topic, and this will give you the beacon’s code. On the opposite side of the area to the terminal you can use this code on a keypad. Doing so will dispense a new repair beacon for you.
With the repair beacon in your possession, make your way through to the room at the far end of the floor. Here, you can access an elevator which you can find behind a laser grid. The elevator will take you to a new room where you can place the repair beacon into a Beacon Launcher. When you do this, it causes a giant machine to drill up to the surface; The Motherlode itself. Once it departs again, head up the steps to its Docking Station Dispenser to complete the quest and collect your rewards. For completing this quest, you’ll receive random ore, components, and a weapon. Most importantly, however, you’ll receive ultracite ore.
Interestingly, once you complete this quest, the Motherlode will occasionally appear in Ash Heap. Its appearance is part of “The Motherlode” event quest, which offers further rewards of Nitrocite. However, you won’t see this quest available unless you’ve completed this side quest first.